The ACT English section will sometimes test your knowledge of preposition usage; knowledge is the keyword here, since you really cannot reason your way through the intricacies of preposition usage. For this reason, we often refer to preposition questions as “idiom” questions; simply put, an idiom is a recognized grammatical construction that is a rule simply because of tradition. The idiom constitutes the ultimate tautology: we say something a certain way because, well, that’s how we say it.

Preposition usage is notoriously arbitrary, or, as the test-writers might say, preposition usage is idiomatic. Why do I listen “to” the radio instead of listen “at” the radio? We say “listen to” because that is how English speakers have said it for hundreds of years. We like it that way, and we are not willing to change.

For some students, idiom errors can be the easiest to spot on the exam. To these students, an idiom error sticks out like a sore thumb. When they read something like “listen at the radio,” they hear dissonance. The only way to restore grammatical harmony is to replace the grating “at” with the soothing “to.” Balance is restored.

Not everybody thinks this way. For many who learned English as a second language, and even for those who have a purely logical–as opposed to intuitive–understanding of language, idiom errors are extremely difficult to detect. After all, there is no logical explanation for why we say “listen to” instead of “listen at.”

Even if you think you know English idioms like the back of your hand, take a glance at the following list of verbs, adjectives, and nouns and the prepositions that accompany them. You may find that you’ve been saying something incorrectly all this time (gasp!).

While most of the word pairs in the list above will be obvious to you, try to find those with which you are not so familiar. Even better, if you find a preposition that sounds weird to you or even wrong, practice writing sentences with its correct usage and use the phrase in everyday speech. The more familiar these constructions become, the easier it will be to identify when they are used incorrectly.

Try these examples to exercise your new idiom savvy:

Idiom Question 1

I am preoccupied about my studies.

Idiom Question 1 - Correction

I am preoccupied with my studies.

Idiom Question 2

She had a fondness toward dolls when she was little.

Idiom Question 2 - Correction

She had a fondness for dolls when she was little.

Idiom Question 3

The ACT consists in four sections: Math, Reading, English, and Science.

Idiom Question 3 - Correction

The SAT consists of four sections: Math, Reading, English, and Science.

Idiom Question 4

John’s awareness about global warming encouraged him to study ecology.